* detect version option before all other oprion parsing

jackd now checks its arguments for "-V" and "--version" before all other
option parsing happens.

* remove some dead code from option parsing

Version options are detected before optparse runs, the removed code
paths thus became obsolete.

* remove rest of version option from optparse

Detection of the version option is now handled outside of optparse, thus
left over stings and variables are removed.

* switch to string comparison for detection version option

Demanding an exact match for the option strings reflects the original
behavior more closely than a search for substrings.